Pliers



Dec. 26, 1950 H. w. STARK EI'AL 2,535,375

PLIERS Filed Nov. 17, 1947 INVENTORS. & meow W. STA/2k a4 BUY A. GPA/VT Patented Dec. 26, 1950 UNITED STATES. PATENT OFFICE PLIERS Harold wftark: and Roy A. Grant, Marinette, Wis.

Application November 17, 1947, Serial Navsasss 2 Claims.

This invention relates to pliers having adjustable clamping jaws.

An object of this invention is to provide a pair of pliers which include a pair of pivotally connected together handles or pressure levers, a pair of article clamping jaws pivotally connected to said handles, and anadjustable fulcrum pin connected between said jaws. l Another object of this invention isto provide a pair of pliers which include'a pair of pivotally connected together'handles or pressure levers, a pair of article clamping jaws, and means pivotally securing the rear ends of said jaws to said handles in a manner to rock saidjaws to clamping position when said handles are swung toward each other.

Another object of this invention is toprovide a pair of pliers of this kind which are particularly designedfor use as dental forceps and which include means for adjusting the jaws relative to each other so as to grip an article of predetermined size when the handles are closed, the handles when closed placing substantially the same pressure on the article irrespective of the size of the article inasmuch as the jaws have the same movement relative to each other irrespective of the size of the article. P

To the foregoing objects, and others which may hereinafter more fully appear, the invention consists of the novel construction, combination and arrangement of parts, as will be more specifically referred to and illustrated in the accompanying drawings, but it is to be understood that changes, variations, and modifications may be resorted to which fall within the scope of the i invention as claimed.

In the drawing: v

Figure 1 is' a detailed side elevation of a pair of pliers constructed according to an embodiment of this invention.

Figure 2 is a plan view of the pliers.

Figure 3 is a longitudinal section through the forward end of the pliers showing the jaws in open position.

Figure 4 is a sectional view taken on the line 4-4 of Figure 1.

Figure 5 is a sectional view taken on the line 5--5 of Figure 1.

Referring to the drawing, the numerals l and II designate generally a pair of elongated handles. The handle H is substantially shorter in length than the handle l0 and is provided at its rear end with an outwardly curved rear portion l3. The handle H! at its forward end portion is provided with an angularly disposed pair of ears 2 l2 between which an angularly disposed ear l4 carried by the forward end of the handle II is adapted to engage. The cars l2 and M are pivotally connected together by means of a pivot I 5. A pair of jaw members, generally designated as US and I1, extend from the handles and II, respectively. The jaw member I6 is pivotally connected to the forward end of the handle ID by means of a pivot [8 which is offset laterally from the pivot l2 and the jaw member I! is pivotally connected to the forward end of the handle H by means of a pivot l9 which is offset laterally from the pivot [5. The jaw member l6 includes an elongated shankwhich is provided with a'curved forward end 2| terminating in a pressure applying jaw 22.

The jaw member 11 includes an elongated shank 23 disposed in parallel relation with respect to the shank 20 when the handles 10 and II are in closed position. The shank 23 has extending therefrom a complementary forward end portion 24 and a pressure applying jaw 25 is carried by the extension 24.

In the present instance, as shown in Figure 5, the pressure applying jaws 22 and 25 are formed with concave confronting faces 26 and 21, respectively. The jaws I6 and I! are adapted to be constantly urged apart by means of a flat spring 28 which extends between the shanks 20 and 23, bearing at its outer portion against the shank 28 and provided with an inner portion 29 which bears against the ear M. The jaw members It and I! are pivotally connected together and are adjustable relative to each other by means of a threaded bolt 3!) which is extended through the shanks l6 and I1 and is provided with a head 3| engaging in a socket 32 formed in the shank 23.

The shanks 20 and 23 are provided with openings 33 and 34, respectively, through which the bolt 35 loosely engages and a nut 35 is adjustably threaded on the bolt and bears against the outer side of the shank 20. The bolt 33 constitutes the fulcrum or pivot member for the jaws l6 and I! and is adapted to be adjusted to provide for the desired opening between the outer jaw or pressure applying members 22 and 25.

In the use and operation of these pliers the jaw members !5 and I? are initially roughly adjusted relative to each other by adjustment of the nut on the bolt 36. This will permit the spring 28 to move the outer ends of the jaws apart a distance sufficient to receive the article which is to b engaged by the jaws therebetween. The rocking of the handles Ill and H toward each other will provide for limited movement of the outer ends of the jaws toward each other so that the necessary pressur of the jaws on the article will be limited and the handles l and I I will normally be in closed position when the article is clamped between the jaws. These pliers have been designed partly as dental pliers or forceps so that the necessary pressure may be applied to a tooth in extracting the latter and the jaws will not'be placed under undue pressure during the extracting op ration. In this manner the tooth will not be broken off by application of excessive pressure such as is the case where ordinary pliers are used.

Due to the ofiset connection between the handles it and II and the clampin members it and I1, respectively, when the handles l5 and H are swung toward each other to effect a gripping of the article, the clamping members IE5 and I! are locked in clamping position and will handles, means pivotally securing the outer ends of said handles together, a pair of elongated. clamping members havingopposed clamping jaws on the outer ends thereof, means pivotally securing the "inner ends of said members to said handles in offset :relation with respect to said first-named pivot :means, andadjustable fulcrum means including a bolt of adjustable effective length extending through said members outwardly of the innerends thereof and in the plane of swinging ot-said clamping members whereby rocking of said handles toward each other will move said clamping jaws toward each other, and whereby adjustment of the eff ctive length of said bolt will vary the limits of movement of said 4 clamping jaws in both the opening and closing directions relative to each other.

2. A pliers comprising a pair of elongated handles, means pivotally securing the outer ends of said handles together, a pair of elongated clamping members having opposed clamping jaws on the outer ends thereof, means pivotally securing the inner ends of said clamping members "to said handles in offset relation with respect to said first named pivot means, spring means interposed between said clamping members for constantly urging said members apart, and adjustable fulcrum means for said clamping members disposed outwardly of the inner ends thereof, said fulcrum means including a bolt of adjustable efiective length extending through said clamping members at right angles to said second named pivot means whereby rocking of said handles toward each other will move said clamping jaws toward each other, and whereby adjustment of th effective length of said bolt will var the limits of movement or said clamping jaws'in both the opening and closing directions.

HAROLD W. STARK.'

ROY A. GRANT.

REFERENCES CITED The following'references are of record in the file of this patent:

UNITED STATES PATENTS France Sept. 22, 3903 

